The Tacoma Parking Technical Advisory Group has recently made three recommendations to the Tacoma City Council in response to the increasing demand for parking in downtown.

The first two — expanding paid parking around the County-City Building and charging full rate on Saturdays by the University of Washington Tacoma — are sound in principle and practice and should be promptly implemented by the council.

However, the third proposal — to reduce time limits from two hours to 90 minutes by the UWT — is misguided and would increase congestion and pollution on Pacific Avenue and create a number of related problems.

The proposal is also contrary to the best practices for parking management and the methodologies of model comparative cities. Although well-intentioned, this proposal should be respectfully declined by the Tacoma City Council.

The “head and shoulder” authority on parking, one which incorporates hundreds of parking studies, is the 733-page text “The High Price of Free Parking,” written by UCLA Urban Planning professor Donald C. Shoup and published by the American Planning Association.

With refreshing clarity, Shoup explains that “the purpose of right-priced curb parking is” to set “the lowest price that will avoid shortages.” In order to avoid such shortages, “traffic engineers usually recommend that about 15 percent of curb space — one space every seven — should remain vacant to ensure easy ingress and egress.” Shoup points out that “this cushion of vacant spaces eliminates the need to cruise.”

Shoup specifically warns against the Tacoma Parking Technical Advisory Group suggestion to reduce time limits in response to increase demand: “Time limits are an inefficient way to manage parking spaces: Such regulations are, almost necessarily, highly inefficient in the regulations of parking space.”

Instead, he suggests that “rather than limit the duration of curb parking, cities can charge the right price for it. What is the right price? The right price will balance the demand for parking — which varies over time — with the fixed supply of parking.”

Shoup also points out that this erroneous approach reduces parking revenue collected and increases traffic congestion, yet it increases tickets and conflicts between drivers as they jostle to acquire underpriced parking spaces.

Traffic congestion is already a significant issue on this stretch of Pacific Avenue. Hence, reducing time limits in response to increased parking demand would exacerbate many of the problems the parking commission seeks to remedy, despite their intentions.

Increasingly, other model cities such as San Francisco and Redwood City are moving to increase or eliminate time limits altogether. It is also incumbent on the City of Tacoma to comply with the ordinance which originally implemented paid parking: It mandates that parking rates be set in a manner to obtain a 15 percent vacancy rate.

Because the demand for parking in downtown Tacoma varies wildly depending on the area, Tacoma should follow the lead of other cities and calibrate the fee for parking with the demand in each area.

While Seattle charges seven different rates for curbside parking depending on the demand in the area, Tacoma has refused to take a nuanced approach and continues to charge one rate for the entire downtown.

This has resulted in overpricing and massive vacancies in some areas of downtown and underpricing and congestion in others. Even Olympia, with a population of less than one fourth of Tacoma is still able to manage four separate parking rates corresponding with the demand in various areas of downtown.

Managing Tacoma’s parking resources competently has been a critical factor to Fitch, the company which recently assigned Tacoma new ratings on three sets of city bonds.

Tacoma’s economic future and the attractiveness and qualify of life largely hinge on the city’s willingness to implement best practices in managing its public resources, including parking.

Erik Bjornson is a mechanical engineer and attorney who works in downtown Tacoma and often writes about downtown urban issues. He edits the Tacoma Urbanist and the Tacoma Sun blogs.